Fertility preservation: the rationale for cryopreservation of the whole ovary

Recently, much progress has been made in the area of cryopreservation of ovarian tissue, one of the only options for fertility preservation available to women who require immediate gonadotoxic chemotherapy. Human ovarian cortical tissue strips have been cryopreserved, thawed, and autotransplanted with successful reproductive function. Cryopreservation of ovarian cortical strips, however, is limited by the ischemia that occurs at the time of retransplantation. Thus for patients that desire long-term resumption of endocrine function, cryopreservation of the whole ovary with an intact pedicle and vascular supply may be a better option. This article describes recent advances in whole ovary cryopreservation in both animal and human models, with a focus on surgical technique for removal, choice of cryoprotectants, freezing and thawing protocols, and preliminary results with organ retransplantation. Although no human cases of whole ovary retransplantation after cryopreservation have been performed to date, these preliminary studies have been encouraging, and it is likely that this option for fertility preservation will be a viable treatment option in the future.